Tag: reduce noise

Hearing loss due to high noise levels is a common problem in many industrial facilities. Without the use of proper PPE, hearing loss can occur quickly. This is a serious concern as hearing loss is permanent and once the damage is done there’s no way to reverse it. Due to this risk, OSHA strictly enforces standard 29 CFR-1910.95(a).

This directive discusses the effects of noise and limits exposure based on the dBA. The table below indicates the maximum allowable exposure time to different noise levels. Sound levels that exceed these levels should first be addressed by proper engineering controls such as isolating the source of the sound from personnel or replacing the cause of the sound with something like an engineered compressed air nozzle. When such controls aren’t feasible, proper PPE must be worn to protect the operator.

Hearing loss can occur in as little as 30 minutes when exposed to sound levels 110 dBA or greater. Operators have a tendency not to use PPE as directed, if an OSHA inspector comes to your facility and notices that the sound levels exceed the maximum allowable level without protection hefty fines will be soon to follow. In this example from the United States Department of Labor, a company was fined a total of $143,000 for failing to protect their employees.

Model 9104 Digital Sound Level Meter

In order to identify the places or processes in your facility that are causing the problems, you’ll need a tool to measure the sound level. EXAIR’s easy to use Digital Sound Level Meter allows you to measure and monitor the sound level pressure in a wide variety of industrial environments. The source of the loud noise can then be identified and isolated so that corrective action can be taken. For compressed air related noise, EXAIR manufactures a wide variety of engineered compressed air products that can reduce the sound level dramatically. In many cases, EXAIR products are capable of reducing noise levels by as much as 10 dBA. Since the dBA scale is logarithmic, this equates to cutting the sound level in half!

Drilled pipes and open ended tubes are the common culprit for excessive noise levels. Replacing them with an engineered solution often eliminates the need for hearing protection.

If there’s processes within your facility that are above these limits and you’d like to eliminate relying on proper PPE, give an Application Engineer a call. We’ll help walk you through the selection process and make sure that when the OSHA inspector comes knocking you’re prepared!

Last week, I received an email from a satisfied customer, after he had already purchased our product. Come to find out this customer had not spoken to an application engineer during the planning stage to make their purchase. With our excellent resources listed at EXAIR.com, the customer was able to fulfill his application without even speaking to us. After his initial email of thanks, he also shared with me some details of his application that I want to share with you today.

The customer works as a machinist at a large aircraft part manufacturer. The parts require a very tight tolerance. A sample of each part needed to be gauged and measured in an automatic thread gauging machine or a coordinate-measuring machine (CMM). Their machining process required a water based flood coolant, so each part would be coated in water based coolant and chips, which needed to be remove before gauging. Before visiting EXAIR’s site, the company used a variety of homemade and commercial blow offs, as safety air gun tips. Here is a photo of (20) of the (25) nozzles the customer was using.

As you can see, the nozzles vary in design purpose, flow and safety. Most of the nozzles feature a cross drilled hole or a secondary escape path, but not all of the nozzles do. Any nozzle without a secondary relief port violates OSHA standard CFR 1910.242(b), so replacing some of the nozzles increased the safety in the plant. Secondly, these nozzles are wasteful in their use of compressed air because some were designed as liquid nozzles and have large exit holes. A hole that is 1/8″ in diameter at the nozzle outlet can consume up to 21.4 SCFM of compressed air at 80 PSIG. For comparison, the model 1103 Mini Super Air Nozzle with a 1/8″ NPT inlet will flow 10 SCFM at 80 PSIG, which would be a 53% compressed air savings. In 24 running hours, the 1103 nozzle will save 16,416 Standard Cubic Feet, which the plant spent $4.10 for a standard industrial compressor to produce (The standard for compressed air cost is $0.25 per 1,000 SCF). Replacing just one 1/8″ drilled hole with 1103 Mini Super Air Nozzle saves the aircraft company $1,026 over 250 working days running 24 hours a day.

Neither of these were the real reason that the customer emailed to thank us though. He was actually an office employee just entering the work force. Starting in June until after the company finally acquiesced to his request to buy a better, quieter nozzle near the end of July, he had left work needing an aspirin to relieve the headache he acquired due to the noise from these other nozzles. The nozzles the machining center had been using would create noise levels between 88-100 dBA at 80 PSIG of inlet pressure. For reference OSHA mandates that employees are required to wear hearing protection, if they are exposed to noise levels over 90 dBA over an 8 hour work day. The employees doing the machining wear hearing protection, but the employees in the office were still exposed and affected by the noise level. This is just one anecdotal example, but everyday more and more research shows that noise exposure has a negative effect on our health and productivity in the workplace. If you are interested in more information here are some links to a number of studies/research – please read this, here or this.

Anyway, that’s enough of my soapbox. The company purchased 25 of EXAIR’s 1103 Mini Super Air Nozzles and utilizing the same guns they were currently using saw between a 10-15 dBA decrease in noise levels near the work stations. Here is a photo of one of their setups with the model 1103 installed on one of their current air guns.

The 1103 Super Air Nozzle is an engineered solution to replace a plethora of commercial nozzles. It was a simple and cost effective retrofit which increased the comfort of employees.

We know that every time they squeeze that air gun trigger they will be using less compressed air than before, and we know they are now in compliance with OSHA. But the best benefit for EXAIR is we know that the engineer took the time to email us to thank us for taking away his headache everyday. That’s enough for me.

“I know EXAIR makes Air Knives. Do you have one for this application?”

We can answer, almost unequivocally, with a resounding “YES!” Whether we can meet the needs of the application with a stock product, or through manufacturing a specially made unit, we make every effort to provide the needed solution.

Case in point, in the application above, a specific length Air Knife was desired to remove debris from material as it goes into a processing chamber. The current setup (outlined in red) uses drilled holes in a section of pipe which are costly, loud, and unsafe.

How costly, you ask? Our customer stated this knife was 100″ long with 3/32″ holes on 2″ centers (50 holes). EXAIR test results on 3/32″ drilled holes confirm 15 SCFM per hole at 80 PSIG inlet pressure. The customer also estimates this drilled pipe operates for a total of 1 hour every day, 250 days per year. Using $0.25 per 1000 SCFM we can calculate the following:

50 holes x 15 SCFM = 750 SCFM at 80 PSIG

750 SCFM x 60 minutes per day = 45,000 SCF per day

45,000 SCF x 250 days = 11,250,000 SCF per year

11,250,000/1000 x $0.25 = $2812.50 cost per year

How loud, you ask? Our customer confirmed all personnel near the application were require to wear ear protection at all times. Though they were unable to provide a decibel (dBA) level, the need for hearing protection would indicate this pipe was operating in excess of 100 dBA.

How unsafe, you ask? Air can be dangerous when the outlet pressure of a hole is greater than 30 PSIG. In the event any of the holes were blocked by a hand or other body part, air may enter the bloodstream through the skin, resulting in serious injury. All of the Air Knives manufactured by EXAIR have been engineered for safety. They are all safe to be supplied with higher pressure compressed air and meet OSHA standard CFR 1910.242(b). Drilled holes in a pipe DO NOT MEET this OSHA standard.

Initially, discussions with this end user focused on a custom length, custom built Super Air Knife. Given the dimensions of the processing environment, we determined the desired length and the end user was thrilled we could not only make to their specifications, but offer 3 day delivery as well.

As the discussion carried on, we realized that the special length Super Air Knife, while applicable, was not a critical requirement for the application. With this new consideration, a stock length knife was chosen, and just like any stock EXAIR product, we had it on the shelf, ready to ship the same day.

This application highlights several benefits of the EXAIR Super Air Knife solution – compressed air savings, noise reduction, providing safety, and quick delivery. EXAIR Super Air Knives solve multiple problems for end users and OEM’s in a variety of applications.

Switching this customer over to an engineered solution provided a win in these three important areas of any operation. If assistance is needed determining which Super Air Knife best suits your application, contact an Application Engineer.